Sludge or slurry having waste materials intermixed therein poses a problem in today's industry. In the metallurgical industry, there is no suitable way of treating sludge from coke plants, blast furnaces, converters and rolling mills, for example oil-contamined scales and hydroxides from pickling. In most cases, these materials are deposited in some intermediate storage or taken to a landfill. Another area in which the problem of recovering materials is present is the petrochemical industry, wherein a waste product in the form of sludge is created.
The pressure from both public authorities and customers to find new solutions is constantly increasing. The earlier solution of land-filling is no longer a feasible solution and is in many countries illegal. Existing techniques for conversion and recovery are costly.
From an economic and environmental point of view, recovery is often a preferred solution to the above-mentioned problem of taking care of the waste material. However, recovery often means some kind of external processing, resulting in transportation to plants and processes lying beside the normal chain of processes.
A known solution to these problems is pelletization or briquetting of the waste material for subsequent feeding to a furnace. However, this solution is accompanied with the problem of extra costs for a separate plant for drying and subsequent pelletization of the waste material.
The patent document DE 24 60 799 discloses a method of burning oil containing metal particles. The object of the disclosed method is the destruction of the oil while avoiding unwanted exhaust particles. The burning relies solely on the energy supplied by the oil itself.
The patent document DE 42 41 283 discloses a process of gasification wherein particles are recovered. No separate fuel supply is provided.